Flat roofs have long been problemsome because of leaks. Many improvements have been developed such as built up roofs, IRMA or inverted roofs where the waterproof membrane is located beneath the insulation layer, continuous membrane roofs and the like, but on occasion leaks do occur. Such leaks can and generally occur at the most inopportune time and location. As is well known, leaking water rarely travels in a straight line, rather it follows beams or girders to a different location; often causing expensive damage to equipment and/or decor. Until now roof repairs must await the cessation of the rain when the roof once again is dry. The instant invention permits the blockage of the leak during the rain reducing or eliminating damage being caused by the leak.